[FFmpeg-devel] [RFC] allow mpegts demuxer to reload streamsifservice disappears

elupus elupus
Tue Jul 17 00:55:51 CEST 2007

"M?ns Rullg?rd" <mans at mansr.com> wrote in message 
news:yw1x4pk46lqh.fsf at thrashbarg.mansr.com...
"elupus" <elupus at ecce.se> writes:


> Can you capture a stream where this change is needed?  I'd like to
> have a look.

Obviously I wasn't smart enough to store the stream i originally had 
problems with (streaming directly from tuner card). But i expect the issue 
would crop up again if i swapped between a h264 encoded channel and one with 
standard mpeg2. The video would still come on the same PID. if now SVT-HD 
would start up where i live on dvb-t it would be easy to reproduce.

I think in my case the issue came from an mp2 -> ac3 switch, but alas now i 
can't find any channel where it ends up that way. I think the tvserver sends 
the first audio stream it finds in the source on a fixed pid, then the 
second it finds on on one pid larger. same goes for video.

so if on a channel change, the order things show up differs. ie it finds the 
ac3 stream first, instead of mp2 the pid's may swap. it correctly generates 
a new pat/pmt with a new version number on this change. so i don't think 
it's doing anything wrong.

will let you know if I manage to capture such a stream again. might be easy 
to generate one by just concating two ts streams togheter which happen to 
use same pid for two different things.


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